WNBM's broadcast frequency of 103.9 MHz was originally occupied by WFAS-FM, which first signed on the air September 1, 1947. Licensed to White Plains, New York, the station's targeted listening area was Westchester County and the lower Hudson Valley region. WFAS-FM initially simulcast sister stationWFAS before adopting a separate full-service format; it later evolved into an easy listening station, and then an adult contemporary outlet by the mid-1980s. Its primary competitor through much of its history was another regional FM station, WHUD.
In order to increase their reach of the New York metropolitan market, as well as increasing the value of the station, in 2012 Cumulus applied to the Federal Communications Commission for a construction permit to move the station's transmitter tower location to the Bronx and subsequently change the station's community of license to Bronxville, all in order to better target New York City itself. The permit was approved in mid-2013. Rumors on radio industry insider websites speculated that the station would change its programming format, and flip to either urban contemporary or modern rock. On June 30, 2014, WFAS-FM's existing on-air staff departed. Five daya later, at Midnight on July 4, WFAS-FM signed off its transmitter, after a set of "goodbye"-themed songs, which ended with "Graduation " by Vitamin C. Later that day at 9:00 a.m., the new Bronx transmitter signed on, and 103.9 FM began stunting with a ticking clock, and at 1:03 p.m., the station officially flipped to Urban adult contemporary as "Radio 103.9" under the new callsign WNBM. The WFAS-FM callsign and its programming continued to exist via online streaming and as the HD2 sub-channel of sister FM station WPLJ. Additionally, on August 29, 2014 at 2:00 p.m., "WFAS" returned to the analog airwaves, broadcasting on W232AL at 94.3 MHz. WNBM's primary competition is WBLS, New York City's heritage Urban Adult Contemporary outlet. The station serves as the New York affiliate of D.L. Hughley's syndicated afternoon program, which is distributed by Urban One-owned Reach Media. WNBM also carried the Tom JoynerMorning Show from the station's launch until Tom Joyner's retirement at the end of 2019. Throughout 2019, Cumulus began to withdraw from the New York market in earnest to pay down debts from its 2018 bankruptcy, selling WPLJ to the Educational Media Foundation, WNSH to Entercom, and WABC to John Catsimatidis's Red Apple Media; after the WABC sale announcement, Cumulus stated that WNBM would be divested as well. WNBM's AM sister station, WFAS, runs automated as a CBS Sports Radio affiliate, freeing WFAN from carrying programming from its network. On November 8, 2019, WNBM, in anticipation of a future sale, ceased live programming and became fully automated, terminating its remaining airstaff in the process. In all time periods outside of the Hughley program, the station carries Westwood One's Adult Urban Contemporary-formatted The Touch radio service, delivered via satellite. With the 2019–20 coronavirus pandemic effectively ensuring a sale will not occur in the near future, the station added the Westwood One-distributed, Atlanta-basedRick & Sasha program to mornings in late April 2020.
